1. Confirm your Outlook data is correct.
2. Connect your BlackBerry to the USB > Desktop Manager > Backup/Restore > Advanced.
3. In the RIGHT hand pane, you will see your device data. Scroll down to the Address Book data, so that line is highlighted. Click the CLEAR button below. This will delete ALL the Address book data on your device.
4. Sync your Outlook data to the BlackBerry as you would normally.

Good luck.

I got the ALMOST same problem with dr997 above. I checked the "sync contacts" option on the email setup in my BB. After the sync process completed, I noticed that SOME of my contacts disappeared on the BB, but when I check my gmail via gmail.com, I found around new 4,000 (yes 4 thousand) contact existed on the gmail account.

The rest of the story similar to dr997.. Basically I could NOT restore the contacts to my BB even from Advance setting (using the most recent back-up data). At the Advance window, I got the following message:

"Databases that are unvailable in the list have been configured for wireless sync or wireless backup and are read-only. you can not restore or clear them"

VERY frustrating.

I also FAILED to sync my contacts from MS Outlook to BB (one way from MS Outlook to BB). I tried a few attemps, each time I got different result. Some (random) contacts are always missing in the BB. Sometime all contacts start with "B" are missing and another attemp all contacts start with "E" are missing..

On top of that, now when I press short cut "s" from home screen to search.. I could NOT find the Contact field any longer...weird huh!

I also check in Option> Status> Menu and Database Size
I could NO longer see Address Book there....

VERY VERY frustrating...

@JSANDER I tried to follow above steps BUT I coud NOT clear the Address book on the RIGHT pane in Advance setting. All I could see in the RIGHT hand pane (on the device) only one "Address Book - Last Used Hints" I could NO longer see NOR find any other Address Book data...(ussually you could see the number of contact beside it)

Now when I highlight this "Address Book - Last Used Hints" and hit CLEAR button at the bottom, it did NOT cause any changes in my contacts in my BB. The contacts remain the same as is...

At the bottom of the pane I could see the following message:
"Databases that are unvailable in the list have been configured for wireless sync or wireless backup and are read-only. you can not restore or clear them"

I have total around 6,000 contacts in my BB with each contact consist of detail info (home phone, work phone, email etc etc). I could NOT afford to re-type one by one...Please urgently help... Greatly appreciate for the help...